Clausiliidae

Clausiliidae
Cochlodina laminata
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
(unranked): clade Heterobranchia

clade Euthyneura
clade Panpulmonata
clade Eupulmonata
clade Stylommatophora
informal group Sigmurethra

Superfamily: Clausilioidea
Family: Clausiliidae
J. E. Gray, 1855[1]
Type genus
Clausilia

Clausiliidae, common name door snails, are a taxonomic family of small, very elongate, mostly left-handed, air-breathing land snails, sinistral terrestrial pulmonate gastropod mollusks.

With about 1,300 species recent and fossil, this belong among the most diverse families of land gastropods (cf. Orthalicidae, although the marine gastropod family Pyramidellidae is larger).

Most species of Clausiliidae have an anatomical structure known as a clausilium, which enables the snail to close off the aperture of the shell with a sliding "door".

Shell description

Megalophaedusa martensi is the largest species of the family Clausiliidae in the world. The individual in the photograph has a shell which is 45.5 mm long. The whole snail weighs 3.2 g live.

Almost all the species of snails in the family of door snails are left-handed, which is an uncommon feature in gastropod shells in general.

These snails have shells which are extremely high-spired, with numerous whorls.

The shells tend to be club-shaped, tapering at both ends to a rounded nub. The aperture usually has visible folds.

The clausilium

Main article: clausilium
The clausilium of Clausilia dubia

Clausiliids are also very unusual among pulmonate gastropods in that most of them have a "door" or clausilium. The clausilium is not the same thing as an operculum, which does not exist at all in pulmonate gastropods.

The clausilium is a calcareous structure, tongue-shaped or spoon-shaped, which can close the aperture of the snail shell to protect the soft parts against predation by animals such as carnivorous beetle larvae. The narrow end of the clausilium slides in the grooves that are formed by the folds on the inside of the shell.

Anatomy

In this family, the number of haploid chromosomes lies between 21 and 30 (according to the values in this table).[2]

Taxonomy

The type genus is Clausilia Draparnaud, 1805.

The Clausiliidae family is classified within the informal group Sigmurethra, itself belonging to the clade Stylommatophora within the clade Eupulmonata (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005).[3]

2005 taxonomy

The taxonomy of the Gastropoda by Bouchet & Rocroi, 2005 recognizes subfamilies as follows:

subfamily Clausiliinae Gray, 1855

subfamily Alopiinae A. J. Wagner, 1913

subfamily Baleinae A. J. Wagner, 1913 - synonyms: Laciniariini H. Nordsieck, 1963; Tristaniinae Schileyko, 1999

subfamily † Constrictinae H. Nordsieck, 1981[4]

subfamily Garnieriinae C. Boettger, 1926

subfamily † Eualopiinae H. Nordsieck, 1978

subfamily Laminiferinae Wenz, 1923

subfamily Mentissoideinae Lindholm, 1924

subfamily Neniinae Wenz, 1923 - Neniastrinae H. B. Baker, 1930

subfamily Phaedusinae A. J. Wagner, 1922

subfamily Serrulininae Ehrmann, 1927

Genera

Genera include:

Clausiliinae

tribe Clausiliini

tribe Gracillariini

Alopiinae

Alopiinae[9]

tribe Alopiini

tribe Cochlodinini

tribe Delimini

tribe Medorini H. Nordsieck, 1997

tribe Montenegrinini

Baleinae

Constrictinae

Fossil subfamily Constrictinae contains genera:

Garnieriinae

Eualopiinae

Fossil subfamily Eualopiinae contains genera:

tribe † Eualopiini

tribe † Rillyini

Laminiferinae

Mentissoideinae

Neniinae

Phaedusinae

tribe Phaedusini

tribe Megalophaedusini

tribe ?

Serrulininae

Conservation

Although non-marine molluscs appear to be exceptionally vulnerable to extinction,[13] the IUCN Red list listed only 9 species[14] from this family.

References

  1. ↑ J. E. Gray. April 14, 1855. Catalogue of Pulmonata or air-breathing Mollusca in the collection of the British Museum, Part I: 156.
  2. ↑ Barker G. M.: Gastropods on Land: Phylogeny, Diversity and Adaptive Morphology. in Barker G. M. (ed.): The biology of terrestrial molluscs. CABI Publishing, Oxon, UK, 2001, ISBN 0-85199-318-4. 1-146, cited pages: 139 and 142.
  3. 1 2 3 4 5 6 Bouchet P., Rocroi J.-P., Frýda J., Hausdorf B., Ponder W., Valdés Á. & Warén A. (2005). "Classification and nomenclator of gastropod families". Malacologia: International Journal of Malacology (Hackenheim, Germany: ConchBooks) 47 (1-2): 1–397. ISBN 3-925919-72-4. ISSN 0076-2997.
  4. ↑ Nordsieck H. (1981). Archiv für Molluskenkunde 111(1-3): 101.
  5. ↑ Nordsieck H. (1978). Archiv für Molluskenkunde 109(1-3): 104.
  6. ↑ Nordsieck H. (1985). Heldia 1(3): 83.
  7. 1 2 3 4 5 6 7 8 9 "Clausiliini". Fauna Europaea, last update 27 January 2011, accessed 27 April 2011.
  8. ↑ "Graciliaria". Fauna Europaea, last update 27 January 2011, accessed 27 April 2011.
  9. ↑ Uit de Weerd D. R. (2004). "Molecular phylogenetic history of eastern Mediterranean Alopiinae, a group of morphologically indeterminate land snails". Doctoral thesis, Leiden University, ISBN 90-6464-874-3.
  10. ↑ Gittenberger E. & Uit de Weerd D. R. (2009). "Summarizing data on the Inchoatia taxa, including Inchoatia megdova bruggeni subspec. nov. (Gastropoda, Pulmonata, Clausiliidae)" Zoologische Mededelingen 83 http://www.zoologischemededelingen.nl/83/nr03/a08
  11. 1 2 Maassen W. J. M. & Gittenberger E. (2007). "Three new clausiliid land snails from Tonkin, northern Vietnam (Gastropoda: Pulmonata: Clausiliidae)". Zoologische Mededelingen 81(1): http://www.zoologischemededelingen.nl/81/nr01/a10
  12. ↑ cf. Nordsieck H. (2006). "Species list of recent Clausiliidae".
  13. ↑ Lydeard, C.; Cowie R.; Ponder, W.F.; et al. (April 2004). "The global decline of nonmarine mollusks" (PDF). BioScience 54: 321–330. doi:10.1641/0006-3568(2004)054[0321:TGDONM]2.0.CO;2. Retrieved 20 Oct 2009.
  14. ↑ IUCN 2009. IUCN Red List of Threatened Species. Version 2009.2. <www.iucnredlist.org>. Downloaded on 5 March 2010.

Further reading

External links

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